I am not sure if this is possible, but it would be great to have a watch app for calculating pace strategy for marathons (perhaps even other distances).
I.e. the user sets 4:00:00 as time. A pace (e.g. min/km) of 5:31 for 30km then the app calculates minimum pace for remaining 11.2 km. And/or user marks 10 km pace of 6:00 10km pace of 5:30 10 km pace of 5:40 and 11.2 km pace of 6:00 the app gives the user a finishing time.
This would free me of pen and paper as I am (for my next race) planning on a 4hr time and I know that physiology will not let me keep an even 5:41 pace...so I will have to run harder at the beginning.
I do not believe I am the only one with this problem.
Bonus would be for the app to be able to work as a "data field" if one would want to have pace optimization visual during a race.